This invention relates to a forage harvester and more particularly to an improved removable cutter screen mounted over the discharge opening of the cutterhead housing adjacent to the periphery of a reel type cutterhead to further reduce the crop before it is discharged.
Recutter screen for reel or cylinder type cutterheads are well known, such a recutter screen being shown in the U.S. Pat. No. 3,525,375 also assigned to the assignee herein. Earlier recutter screens generally had square or circular apertures in the screen, and the apertures in the recutter screen in said U.S. Pat. No. 3,525,375 represented an improvement over the earlier recutter screens in that the apertures were elongated and extended in a diagonal direction relative to the cutterhead axis, the cutterhead in said patent being provided with helical knives. One of the features of the recutter screen in said patent was the convenient means for adjusting the rearward end of the screen relative to the cutterhead periphery to obtain minimum clearance between the cutterhead knives and the screen at the rearward end of the apertures.
A later version of a similar recutter screen utilized in self-propelled forage harvesters manufactured by Deere & Co., the assignee of the present application, features a recutter screen having a greater circumferential dimension than the screen shown in said U.S. Pat. No. 3,525,375, with the diagonally elongated apertures being arranged in two transversely extending rows, all of the apertures extending at the same angle so that the opposite elongated sides of all the apertures were parallel.
Recently an improved cylinder type cutterhead was developed for use in such forage harvesters, the improved cutterhead featuring a large number of relatively short knives arranged in circumferential rows, each knife having a straight cutting edge parallel to the axis of the cutterhead. Such a cutterhead is disclosed in U.S. Pat. No. 4,061,284 also assigned to the assignee herein.